Production of isobutyric acid (iHOBu) is accomplished by the catalyzed or uncatalyzed oxidation of isobutyraldehyde (iHBu). FIG. 1 illustrates that the oxidation of the aldehyde results in the formation, first of peroxyacid, followed by the generation of an intermediate that can lead to production of two moles of the desired acid (Pathway A), with an undesired by-product, isopropyl formate (IPF), produced by the Bayer-Villager oxidation of isobutyraldehyde (Pathway B).

As seen in FIG. 1, iHBu can form either the desired acid or the undesired byproduct IPF. In Pathway A, the movement of electrons from a C—H bond on the peroxy acid-aldehyde intermediate results in the formation of two moles of the desired carboxylic acid product. In Pathway B, the electrons move from a C—C bond on the intermediate to form one mole of iHOBu and one mole of the undesired IPF byproduct. Low selectivity for Pathway A results in the loss of some of the iHBu feed to form of the undesired byproduct IPF. In view of problems associated with low selectivity of iHBu oxidation, it would be beneficial if Pathway B of the oxidation mechanism could be impeded so that less byproduct IPF will be produced and more desired acid will be produced.
IPF not only consumes valuable raw materials and lowers the production of the desired acid, it also has other drawbacks. For example, IPF byproduct is very difficult to be separated from unreacted starting materials. The separation of IPF from the reaction mixture is usually accompanied by unreacted isobutyraldehyde (iHBu) due to the proximity of their boiling points. Accordingly, the formation of IPF by-product is a significant financial burden on commercial production of isobutyric acid.